Many indwelling medical devices have a hollow portion. For example, stents are hollow devices that are inserted into body ducts for preventing narrowing of the duct lumen, for tutoring a dilated lumen or for acting as a substrate for tissue growth. As another example, a catheter may have a hollow portion that may serve to transfer a fluid from outside the body to a body cavity, or for draining fluid from a body cavity. As yet another example, an artificial blood vessel valve has a casing enclosing a space through which blood flows.
International Patent Publication WO03/099166 discloses an indwelling unravable medical device having a hollow portion, such as a stent. The device has a generally helical seam which is a weakened region in the wall of the device. When it is desirable to remove the indwelling device from the body, an end of the device is grasped and pulled. As the end is pulled, the seam splits so that the device is removed as a slender strip of material.
U.S. Pat. No. 8,119,151 to Heidner et al discloses a method for coating portions of a medical device. A layer of coating is applied to a surface of a medical device with an applicator. While the coating is being applied, the spreader is positioned in contact with the coating to reduce the coating thickness by spreading the coating over a larger surface area of the target surface.
US Patent Publication 20120029616 of Guerriero et al discloses a method of coating a stent in which the flow rate of a coating material sprayed onto the stent is varied while axially moving the stent. The stent repeatedly passes from one end of the stent to another relative to a major axis of the stent adjacent to a fixed or movable spray nozzle. The axial speed may be varied during spraying of the stent based on the modified flow rate of the coating material to deposit a selected amount of coating material per pass.
U.S. Pat. No. 7,959,999 to Prabhu discloses a stent formed by encasing or encapsulating metallic rings in an inner polymeric layer and an outer polymeric to layer. At least one polymer link connects adjacent metallic rings. The stent is drug loaded with one or more therapeutic agents or drugs.
US Patent Publication 20090259294 to Cully et al discloses a removable device such as a stent-graft, intended for applications where it may be desirable to remove the device at some time following implantation. The stent-graft includes a helically-wound stent provided with a covering of graft material. It is removable by gripping an end of the helically-wound stent component with a retrieval device and applying tension to the stent component in the direction in which it is intended to be withdrawn from the site of implantation.
US Patent Publication 20090192593 to Meyer et al discloses implantable medical devices, such as a stent, for delivering a therapeutic agent, and methods for making such medical devices. In one embodiment, the medical device comprises a stent having a plurality of struts, at least one of which has a cavity disposed therein. A therapeutic agent is delivered from the cavity through and opening in a strut surface.